Thermal Decomposition of Tin(II) Oxyhydroxide and Subsequent Oxidation in Air: Kinetic Deconvolution of Overlapping Heterogeneous Processes

Abstract

The reaction pathway and mechanistic features of the synthesis of SnO 2 via the oxidative decomposition of tin(II) oxyhydroxide in air were investigated using thermoanalytical techniques and morphological observations. Furthermore, the detailed kinetics of each component process were analyzed by applying an empirical kinetic deconvolution method. The thermal behavior of tin(II) oxyhydroxide in air is characterized by two overall processes: (1) the mass-change process, which involves thermal decomposition (mass loss) and in situ oxidation (mass gain), followed by (2) crystal growth of the product SnO 2 . The mass-change process comprises largely overlapping consecutive processes such as primary endothermic thermal decomposition and subsequent exothermic oxidation. It was deduced from the kinetic results that the overall mass-change process is regulated by the overlapping structures of the surface product layers of the primary and subsequent reactions and the counter diffusion of the H 2 O generated in the primary reaction and the reactant O 2 required for the subsequent reaction in the outer layer. The crystal growth of the asproduced SnO 2 occurs via two concurrent kinetic processes that result in the development of a two-dimensional stacking structure. These kinetic features are the key to controlling the overall reaction process and the morphology of the SnO 2 product.

Tin and Lead Alkoxides of Ethylene Glycol and Glycerol and their Decomposition to Oxide Materials

“…Nanostructured SnO 2 has received considerable interest due to its potential application for gas sensing, catalysis, lithium ion batteries, solar cells, etc . While SnO 2 is often directly precipitated by solution‐based methods, it may also be prepared by the synthesis of a suitable solid precursor like tin(II) oxide hydroxide, Sn 6 O 4 (OH) 4 , which is then thermally decomposed to SnO 2 in an oxidizing atmosphere. The precursor decomposition method normally yields highly crystalline samples and provides good reproducibility …”

“…The reason for the unusual TG curve might be a complex overlapping of the decomposition reaction of the (C 2 H 4 O 2 ) 2– ligands and possible redox‐reactions between tin(II) and tin(IV) oxide. Overlapping reactions during the thermal decomposition to SnO 2 can also be observed with other tin(II) precursors like Sn 6 O 4 (OH) 4 . However, the presence of an unknown by‐product with a decomposition behavior that is different from Sn(C 2 H 4 O 2 ) cannot be entirely ruled out.…”

Surface and Adhesion Characteristics of Current and Next Generation Steel Packaging Materials

“…5c. The growth in oxide is a result of the thermal dehydration of the hydroxide which undergoes a corresponding reduction in relative abundance [13].…”

Kinetic characterization of multistep thermal oxidation of carbon/carbon composite in flowing air

“…When the mutual interactions of the component reaction steps are negligible, the overall rate behavior of the oxidation reaction is expressed by the cumulative kinetic equation of the two reaction steps [35][36][37][38][39][40][41][42].…”

“…The aim of this study is to establish a test method for characterizing the compositional and structural properties of a carbon/carbon composite through kinetic analysis of its thermal oxidation process. Kinetic deconvolution analysis of the thermoanalytical data recently used to gain a detailed understanding of the various types of multistep solid-state and solid-gas reactions [35][36][37][38][39][40][41][42] was applied as the most suitable approach to describe the kinetic phenomena of the thermal oxidation process with the aid of the results of fundamental kinetic calculations and morphological observations of the samples during the reaction. This article reports a detailed comparison of the kinetic characteristics of the thermal oxidation processes of two different mechanical pencil leads manufactured by different companies as the first part of our study, which is expected to provide the necessary information to establish the methodology of kinetic analysis as a test method that is generally applicable to various carbon/carbon composites.…”